1. Field of the Invention
The present invention relates to treatment devices for conducting natural orifice treatment to tissue.
2. Background Art
Endoscopic procedures for extracting a calculus from the bile duct may sometimes meet with difficulty in extracting the calculus from a narrow condition of the papilla, that is, the exit of the bile duct. The calculus in this case is extracted by incising spincter muscles around the papilla by using a papillotome passed through an endoscope and expanding the exit of the bile duct. Generally spincter muscles around the papilla are incised in a direction of an encircling fold. The direction of the encircling fold conforms to the direction of the bile duct extending around the papilla and may be subject to less bleeding because relatively few blood vessels existing in this direction.
Inserting an endoscope suitable for pancreatic-and-biliary endoscopy into the duodenum can obtain an image showing the bile duct directed in a twelve-o'clock direction. An endoscope of this type is provided with a raising block that can move the papillotome up and down in the twelve-o'clock direction. Furthermore, a papillotome inserted using the pancreatic-and-biliary endoscopy for incising a teat spinster muscles is manufactured so that a knife portion thereof is automatically directed in the twelve-o'clock direction in an image endoscopically obtained when the papillotome protrudes from the distal end of the endoscope.
The knife portion of the papillotome is stretched for incision. The knife portion separated alone from a sheath is compressed onto the papilla. This provides significant pressure between the knife portion and the incised part of the tissue. Tilting the raising block while supplying electric current to the knife portion causes the distal end of the papillotome to move in the twelve-o'clock direction, thereby incising the papilla.
However, the direction of the bile duct in the vicinity of the papilla may be different from the twelve-o'clock direction in the endoscopically obtained image in some cases including, e.g., variations among individual patients, strictures existing in organs like the duodenum around the bile duct, or surgery in the past.
To address this, an object of conventional papillotomes is to facilitate incision also in non-twelve-o'clock directions while observing an endoscopically obtained image. Papillotomes of this type are provided with a member for transmitting rotation torque produced at a proximate end to the distal end of a knife portion. For example, Japanese Unexamined Patent Application, First Publication No. H9-285472 describes transmitting of rotation torque by using a plate inserted in the vicinity of the center of a sheath. A distal end section of a conductive wire is connected to the plate. Rotating a knife portion that is at the distal end section of the conductive wire causes the direction of the knife portion to be adjusted accordingly.